


The Phantom Obsidian

by sungold_summer



Category: Sonic the Hedgehog (Video Games), Sonic the Hedgehog - All Media Types
Genre: Gen, Panic Attacks, Sonic 2006, Sonic Forces, glitching, just in case that's not your cup of tea, physical glitching, two villains speedrun sonic 06
Language: English
Status: In-Progress
Published: 2020-02-04
Updated: 2020-11-20
Packaged: 2021-02-22 12:47:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,301
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22563631
Author URL: https://archiveofourown.org/users/sungold_summer/pseuds/sungold_summer
Summary: Infinite loses the phantom ruby, and with it, his grasp on reality. He tumbles through parallel dimensions until an old enemy steps forward to propose a deal. Now working side by side with Mephiles, Infinite decides it's time to go round two with the hedgehogs who ruined his life-- and maybe try his hand at godhood in the process.On the other side of the coin, Silver is a teen desperate to save his future. Shadow is trying to have a moment's peace for once in his life. And Sonic--well, he's got a whole cornucopia of problems, and most of them involve a princess who's a lot more powerful than she appears.(First chapter crossposted on Tumblr)
Relationships: Shadow the Hedgehog/Sonic the Hedgehog, it's mostly just background domestic fluff
Comments: 8
Kudos: 48





	1. Prologue

Infinite knew something was wrong the moment the final kick connected with his chest.

He dropped to the platform like a bag of bricks. Every atom of his body felt like it had staggered left of center by a foot. In a flash his hand was on the phantom ruby, checking it for cracks. There were none. He withdrew, satisfied.

Then the glitching started. It felt like swatches of pins-and-needles numbness pulsing all over his body. Infinite stared at his own hand— there and not-there, flashing in and out— momentarily stunned.

The sound of the blue nuisance’s voice brought Infinite back. His first instinct was mortification. He couldn’t let the hero see he’d won— couldn’t let him see this  _ weakness _ — how dare he look on with such pity?

“This isn’t over!” Infinite shouted over his shoulder, and made a tactical retreat.

His landing at the top of the fortress’ high tower was a clumsy one, all knees and elbows. Infinite was happy he landed at all in this state. Eggman was waiting for him.

“So, Sonic slipped through your fingers a third time, hm?” The doctor said, drumming his fingers on his little flying chariot.

Infinite struggled to raise up onto his knees. “Doctor— the ruby— is failing me—” he gasped. “Its power weakens—”

“I’m sorry to hear that,” Eggman said brightly, his cheer almost disguising the malice underneath. “But I’m afraid there are no sick days in the Eggman Empire.”

With that, he stooped politely and plucked the phantom ruby from Infinite’s chest like a cherry off a sundae. 

The effect was immediate.

Infinite’s vision flooded black. He felt himself dragged bodily into a cold void. His stomach lurched. His limbs— wherever they were in the continuum— tingled with a mixture of numbness and electricity. He tumbled, his sense of up and down completely lost, until— 

He arrived in the familiar emptiness of Null space. It echoed out around him to the edges of vision. Stray blocks floated here and there like schools of fish. Infinite’s nausea subsided. He let himself breathe. To be trapped in a realm of his own making was not such a terrible fate— far better than the one he feared. Hell, he might even find a way out if that infernal blue nuisance had proved anything. Infinite considered this. He reached out for a nearby floating cube.

As he did so, a new wave of energy washed over the space and Infinite arrived at the fearful conclusion that  _ this was not his _ that  _ it did not belong to him anymore _ and the glitching resumed with a vengeance and surged up his arm— 

He felt a colder, emptier, vacuumous void open across his back and suck him in. Infinite opened his eyes for one brilliant second and saw a space station— how did he know that?— shaped like the moon sliced in half— 

— he blinked again and found himself falling over an endless ocean, a floating island on the horizon, shrouded in dense jungle and crowned with a single blindingly green light— 

— and then there were cities, dozens of cities, some crowded with aliens and dying soldiers, some flooded beyond repair— 

— and one city that burned like hell itself. The flashing visions hesitated for a moment, like an object thrown in the air pausing before it plummets, and Infinite imagined this burning city could have been  _ his _ , if only the ruby still remained— 

— his passage through dimensions quickened. Infinite could not keep up at this point. Images flashed before his eyes and were just as quickly replaced. He began to notice an object hanging in the center of his vision, faint, but growing ever stronger, ever more solid, as the visions passed.

It was a crystal.

At its heart it gleamed a deep, inky navy, fading to a blighted and sickly blue-grey at the edges. It was not his ruby, to be sure— but still— the energy that radiated from this crystal engulfed Infinite, awakened his hunger for power, promised with sure finality its all-consuming strength.

Infinite needed no further persuasion. He reached out with both hands and slammed the crystal into his chest.

A flood of icy heat flushed across Infinite’s body like hot water poured over frozen fingers. In an instant he felt whole again, physical and powerful. He flexed his long-lost limbs. Infinite watched with morbid curiosity as blighted blue-grey crept in crystalline flakes over his fingertips. Black vapor billowed from beneath his mask. The fiery red he once wore for the phantom ruby burned itself to ash and smoke until even his gleaming armor took on a tarnish.

The flashing images began to slow. Like a tired carousel or a roulette wheel come to the end, Infinite passed through a few more dimensions lazily— a remote island, staffed with guards; the mansion of some rich brat— before the slipstream set him down in a realm to call his own.

Infinite stood, solid and whole, in a vast barren plain. He took a cautious step. Nothing changed. He kicked at the stony earth. Nothing. He moseyed forwards, spinning a little, marveling at the strange rivers of magma and the even stranger clouded sky. He could learn to be content with dominion over this place, he thought. A coat of paint here, a few slaves there— 

“Welcome,” a voice greeted flatly from behind him.

Infinite whirled on the intruder. His eyes fell on an all-too-familiar face.

“ _ You—! _ ” Infinite roared, his mouth a mess of snarling teeth, and he lunged for Shadow— 

Shadow waved his hand. Infinite went flying backward. He struck the earth, bounced, rolled into a guarded crouch— and stopped.

This wasn’t his Shadow.

A series of eerie details slowly made themselves known. There was the sickly blue-grey striping across the quills where they ought to be red. There was the mouth, hanging flat and unused, like an afterthought on a face. There was the way the head didn’t quite hang upright but lolled, slightly; the limp and doll-like arms— then the eyes, those lime-green and deadened eyes that affirmed beyond a doubt that though this creature wore a poor approximation of Shadow’s form, it was by no means the original.

“You may call me Mephiles,” the Being That Was Not Shadow announced. “There’s something I want you to do for me.”

Infinite rose to his feet. He dusted the dirt from his hands. Now that the initial surprise had worn off, this newcomer did not appear to pose much of a threat. “I am Infinite,” he replied. “Were this any other day I would break your soul from your body for proposing I do you a  _ favor _ . But today I am feeling magnanimous, so I will inform you that I am no hero. My services come at an extraordinarily high price. Pray tell, what could  _ you _ ever possibly offer  _ me _ ?”

“I can give you a chance at revenge.”

“You’ll have to be more specific.”

Mephiles shuffled forward. He gestured lazily with one hand. An image of Shadow— the real one— flickered to life. “You despise Shadow as I do, yes?”

Infinite declined to comment.

“He is  _ happy _ in this world,” Mephiles said, his voice dripping with disgust. “He has found  _ love _ and  _ acceptance _ . Look—” the visions of Shadow swayed, changing from solitary scenes to ones of domestic life surrounded by friends. In every image Shadow looked at ease— not entirely  _ happy _ , per se, but the aggressive sharpness Infinite knew too well was gone from his eyes, replaced with a kind of peace. Infinite’s lip curled into a snarl beneath his mask. 

“You think that’s enough to sway me? Pathetic,” he sneered. “I didn’t escape death just to be courted by the paltry shade of my enemy.” He turned his back on Mephiles and waved him away. “Leave me. I will enact vengeance on my own terms.”

A snake of black smoke coiled around Infinite. In its wake hung Mephiles. He no longer appeared as a half-hearted copy; now his limbs clinked and clacked as growths of crystals, his eyes gazed down as vast pools of burning red. This was no ordinary mimic. Here was a long-dead god forcing the limits of its physical prison. Infinite felt a sickly sense of awe and appreciation wash over him. 

“I did not make myself clear,” Mephiles said. His mouth did not move, but the rocks— the sky, even— echoed all the words for him. His piercing scarlet eyes fixed upon Infinite. “You are here because I willed it. I created the Phantom Obsidian you wear on your chest. The power you feel is mine. Without me you would be no more than a ghost. Do you understand?”

Infinite understood, but not in the way Mephiles intended. He knew the new crystal must draw its energy from somewhere; even the emeralds had their own otherworldly font. But never did he dream that his source was a being he could converse with— or, to that end, potentially influence. The sight of Mephiles floating before him filled Infinite with greed. Surely, here was a being without weakness. If Infinite could steal that power for himself, well— 

“Fascinating,” he breathed.

The response shattered Mephiles’ air of grandiosity. His arms drooped. “...What?”

“Tell me: what power do you hold?”

The deity struggled to regain composure. “I control all of time and space. I am the first nightmare, the first absence of light, and so long as I survive I will be the last.”

Infinite’s wild smile grew two inches. “And would you promise an... _ equitable _ share of this power and dominion should I agree to perform your little task?”

“Everything you draw from the stone is yours.”

Infinite placed a hand to his heart, over the phantom obsidian that pulsed methodically on his chest. His voice purred through his grinning teeth, “Then I give myself to your aid, and find the utmost pleasure in doing so. What do you demand of me?”

If Mephiles was surprised by this sudden declaration, he did not show it. He gestured with one hand. The sky filled with the image of a face Infinite knew intimately: Sonic, the wretched sewer-rat hero of the rebellion. “Kill him,” Mephiles grated. “He is the one who prevents me from ravaging this world.” A whirling portal yawned wide beside him. “This will take you to him.”

Infinite gave a little snorting laugh as he stepped through. “You should have picked something harder.”

**Notes for the Chapter:**

> Hey all! Some of you may have read this on my tumblr (@space-colony-snark), along with the post that got this all started. I'll be updating chapters here now since ao3 is so much nicer about organizing multichapter nonsense.  
> That being said, updates are going to be uhhhh slow. I'll add new chapters when I can, but life sucks sometimes!
> 
> Also! This is technically Baby's First Fanfic so all comments and suggestions are really appreciated! <3


	2. A Very Destructive Butterfly

**Notes for the Chapter:**

> Mild tw for descriptions of a panic attack towards the end of the chapter.

Infinite touched down on a balcony high above an ornate city criss-crossed with canals. The night air burned alive with the light of a thousand torches lining the waterways, the cheers of excited citizens reaching even Infinite’s high perch. Merchants wove through the crowds with cheap toys and decorations. Long gondolas decorated with dancing flames paraded past the crowds.

And yet, despite the scene’s novelty, Infinite felt a twinge of hatred in the back of his mind. The parade, the people— they felt banal, almost, somehow hackneyed and repetitive to the point of disgust.

_ Welcome to Soleanna _ .

The voice echoed through Infinite’s head, a deep vibration pulsing in time from the phantom obsidian. Infinite put a hand over the gem cautiously. 

“I take it that grumbling is you, Mephiles?” he murmured under his breath.

_ Yes. The phantom obsidian contains a fragment of my power, thus, a fragment of myself. I will always be with you. _

Infinite curled his lip at that last statement, though he dare not vocalize his distaste. “Care to inform me of the significance of this...” he waved a hand at the festivities. “... _ ceremony _ , I assume?”

_ Every year the citizens of Soleanna pay homage to their god Solaris. Mortal fools. They have no idea what they’ve done. Soon, very soon, their world will burn. _

Mephiles’ last phrase arrived with an air of hesitation. Infinite cocked his head. “Is that so?”

_ It is what should be! _ The coil of energy inside the obsidian shuddered. A mirage of fire sprang to life before Infinite’s eyes. He witnessed Soleanna ablaze, torrents of flame gushing through the canals, buildings toppled and people screaming. Infinite’s old lust for power came back with a vengeance. Here was the apocalypse he wished to call his own.

_ Long have I dreamed of my true power unleashed. It is my right as a wronged god. To this end I sent a pair of assassins, however—  _

The vision shimmered and died. Infinite stood, once again, over the ceremony.

_ It always comes back to this. My pawns never succeed. The hero never dies. It appears that each force in this game perfectly balances the others, forcing a temporal loop. I have watched these events unfold a thousand times and never once have they surprised me. _

“How infuriating,” Infinite muttered. “Though I don’t see what your little predicament has to do with me.”

_ There is variation within each successive loop. I cannot shift the wheel of fate myself, but perhaps— should I introduce a foreign element, a force unseen in previous instances—  _

“You wish me to be the proverbial butterfly,” Infinite surmised, “A very,  _ very _ destructive butterfly.”

_ Indeed. _

Infinite hardly bothered to watch the events as they unfolded around him. He did not put much stock in the religious affairs of blind fools. What did they expect? Comfort? Guidance? There was no god to answer their pleas or smile upon their offerings, just as there had been no god to answer him. The only deity in Infinite’s mind was the one he planned to be.

Besides, it quickly became apparent that the phantom obsidian could bleed information as well as power. Infinite faintly heard the surprised cry of a woman as she tripped on the cobblestone avenue below, only to glance down in time to see her step on the uneven stone and cry out. A gondola passed— he blinked, and it rounded the corner towards him. What was and what would be nipped on each other’s heels with nerve-wracking effects.

Mephiles’ low voice assured Infinite,  _ This will fade; change the future and the visions will be no more than memories. _

As if Infinite needed another reason to hurry the job along. He gestured sourly over the city. “So, when can I expect a little  _ excitement _ around—  _ oh _ ,” The phantom trails of several dozen missiles streaked past his head. Infinite raised his face to Eggman’s warship. A whole platoon of robots tumbled out of the dull, firelit underbelly. Explosions sounded in the distance. A chorus of frightened screams filled the narrow streets. There it was again, Infinite’s old enthusiasm, his excitement for a world about to be unmade. “ _ Nevermind _ ,” he purred.

_ Enjoy it while you can, _ Mephiles cautioned.

Ah, how quickly the hero arrived. Sonic whirled himself into the fray down below, his form hardly more than an eye-searing streak of blue. Look at him, dancing around the princess on her ceremonial podium. Look at him, so coy with the robots, as if they meant nothing. What did the Doctor want with a princess, anyway? 

The princess in question retreated towards the crux of her ceremonial fire. A scathing insult curled on Infinite’s tongue— how could these people live with a ruler so frail?— but something curious caught his attention first. He felt a spike of energy. There, shrouded in waves of heat washing over the princess’s body, a tiny radiance of... _ something _ emanated from her hands clasped over her chest.

A robot clanked towards the maiden. Before the hero could reach her, before the robot could strike, heat waves engulfed the machine and it exploded in a shower of hot metal.

The princess lowered her hands. Infinite could just make out a chaos emerald glittering at her neck. That explained the energy he felt earlier. Still, it seemed strange to him that its power would manifest as  _ heat _ .

“…Does she always do that?” Infinite asked his guide.

_ Do what? _ Mephiles replied.

Infinite took that to mean  _ no _ , and so kept the curiosity to himself. “Pay no mind,” he murmured. Far below, the blue blur launched into a bout of witty banter against the Doctor. Infinite sagged over the balcony’s railing as though forced to watch a terrible community center play. He gave his claws an experimental flex. “Tell me, where  _ are _ those pesky pawns of yours?”

The obsidian subconsciously nudged Infinite’s head to the right. A young hedgehog observed the princess’ rescue atop a nearby roof, bright embers whirling past his head, his silver fur gleaming in the firelight. 

The absurdity nearly overtook Infinite with malicious cackles. Silver? That two-bit freedom fighter? How wickedly ironic fate could be! “Him?” Infinite scoffed. “Oh, what a poor choice in assassins you had.”

_ You know him? _

Infinite remembered how it felt to heave the dead weight of the rebel into a wall. “...We have history, in a manner of speaking. He rose as the star of the hour after Sonic’s untimely departure and Shadow’s— hm— disappearance. Not a very fixed star, really,” he laid his arms across the balcony’s railing. “He fell harder and faster than the other two.”

_ His anger drives him well. Were it not for his heart, duty would see the job done. _

“I’ll believe it when I see it,” Infinite sneered. 

He lifted up from the balcony and shot across the rooftops towards the makeshift assassin. The flight trajectory felt a little...off. Unlike the ruby’s direct force, the obsidian gave him waves of energy, undulating like the ocean, like the layers of shadow flickering beneath a candle’s flame. The result left Infinite slightly more bouncy in the air than he would have liked. He shook off the failure, pulled himself up short behind the oblivious hedgehog. 

“Hello, Silver,” he announced.

The hero whirled on him, fists bright with psychic energy. “Who are you? How do you know my name?” Though his brows were furrowed with fierce passion, Silver still took a cautious half-step away. The weakness kindled a wicked grin beneath Infinite’s mask. He raised both of his hands in a placating manner.

“There’s no need for fisticuffs, dear friend.” The words dripped like honey from his tongue. “I’m an emissary. The cavalry, if you will. Mephiles sent me.”

Silver lowered his fists. He rubbed the back of his head. “I’m always happy to have a helping hand, I guess,” he ventured. “But aren’t Blaze and I enough?”

“I’m afraid not.”

“What’s that supposed to mean?”

Infinite sauntered past the little hero. He pulled a scattershot of memories from the phantom obsidian, picking the most malleable truths to flavor his lie. Mind games didn’t always have to come with a right hook, after all. “What I mean, my ameteur assasin, is that you  _ fail _ . Two days from now you’ll have a chance to speak with the mark. I don’t know what he says, but it makes you reconsider.”

“ _ No _ ,” Silver whispered.

“You fall in with his friends. You parade about the city with them. You start to think that life could be  _ nice _ , that it could be  _ safe _ and  _ fulfilling _ . But in those final, crucial moments—”

“No,” Silver repeated, desperate.

“You are nowhere to be seen. Sonic lives, the city falls, and the future— yours, mine, and everyone else’s— goes up in flames.”

“No!” Silver slammed his fist down on a decorative facade. He glared up at Infinite. “Tell me what I have to do,” he demanded. “Whatever it is, I’ll do it. I won’t let anyone else suffer because of his actions!”

Infinite stifled a greedy purr at the sound of that veritable blank check. Whatever Mephiles told the little punk, Silver fell for it hook, line, and sinker. He practically had the hero on a golden chain. A dark and delightful idea flitted into Infinite’s head: he’d let this hot-headed nuisance take the first shot at Sonic. It would be just like his phantom copies, only… real.

The jackal lay a careful hand on Silver's shoulder. “Here’s my advice: show no mercy. Give him no quarter, no opportunity to strike back. He’s a tricky devil. He plays so well at being friendly, of being nice, of showing everyone he  _ cares so much _ .” Infinite sneered. “But where is he for the poor souls outside of his bright little clique? Where is he for the sad, the downtrodden, the miserable scamps of the world sent to fight the fights he  _ won’t _ — _? _ ” he broke off with a snarl. “He is nothing but an airheaded mongrel of false hope. Kill him where he stands.”

“...You sound like you have experience,” Silver said.

“In a manner of speaking,” Infinite replied. The hero beside him scoffed sadly.

“Well, I wouldn’t expect anything else from the man who destroyed the world. But I’m not afraid.” Silver flashed Infinite a grim but determined smile. “I promise, I’ll save the future even if it kills me!” 

_ That can be arranged, _ Infinite thought. He watched Silver burst from the roof in a blaze of psychokinetic light. Infinite stepped to the edge of the roof to follow— and paused. “Before I embark on this little mission of yours, I’d like to make a request,” he purred to the voice in his head. “Nothing grand. Think of it as… a show of good faith.”

_ What do you desire? _

“Take me to Shadow. Let me see with my own eyes how kind this world has been to him.” Infinite cracked his knuckles in preparation. “I want a taste of the revenge you’ve promised me.”

* * *

Infinite shuddered at the sudden cold of the phantom obsidian’s equivalent of chaos control, followed swiftly by a harsher, more biting wind. A dark, snow-encrusted forest stretched out before him. The name  _ White Acropolis _ flitted through his mind.

“What a cheery spot,” Infinite groused. He drifted through the bare branches like a ghost. Up on the next hill, a familiar black hedgehog stood among the brush, his form stark against the snow.

“Hello, Shadow,” Infinite snarled to himself. The phantom obsidian flared in anticipation. Where to start, where to start? Fear? Pain? A delightful mix of both? What did this version fear, anyway? Well, Infinite thought with a toss of his head, he’d find out soon enough. 

And then, the godawful sounds of Crush 40 echoed through the forest.

Shadow swore. He ducked behind the nearest tree, pulling a phone from the GUN-issued jacket around his shoulders. The caller ID brought a wry smile on his lips. Shadow answered the call in a hushed tone, almost—but not quite—chiding. “You know you’re not supposed to call me when I’m at work, Blue.”

Shadow rolled his eyes at the ridiculous excuse on the other end. He sauntered away from his cover, kicking at the light snow as he went. “What does he want a princess for?—tch, I never listened to those monologues, even when I was working for him. Your guess is as good as mine.” He stopped at the edge of the hill to survey the base below. “Yeah, yeah. I’ll keep an eye out for her. …Hm? It’s  _ classified _ — I did too read the reports!” Shadow refuted in a stage whisper. “At breakfast, remember? You kept distracting me.” He sighed, waving his hand. “Listen, I have to go play distraction for Rouge. See you tonight.” He paused, added, “...Love you too, Blue.” 

Shadow hung up the phone. A tiny, impossibly endeared smile tugged at the corners of his mouth. He allowed himself one small chuckle.

The phantom obsidian burned cold in Infinite’s chest. The renegade jackal dragged his claws deep into a tree to express the fury he so wished to scream. That—  _ that  _ was not kindness. Peace?  _ Happiness? _ Oh, Mephiles had sold the situation short. Shadow wasn’t just  _ happy _ . The damn fool was in love!

Infinite seethed behind his mask. Deep, inky clouds curled between his teeth. Now was not the time for finesse. He raised one hand and let the full brunt of the phantom obsidian’s energy billow across the forest.

Shadow dropped to his knees, the phone clattering from his hand, his body wracked by overwhelming vertigo and a keen sense of terror. Nothing made sense. His surroundings could not be understood, let alone named. Shadow stared at his shaking hands. He didn’t believe they were his.

Just as soon as the wave struck, it passed. Shadow took a deep breath. He curled up where he lay. “ _ Damn panic attacks, _ ” he hissed. He reached for the discarded phone. Redialed the last number.

“Hey.” he rasped. “I need you to talk me down.”

* * *

Infinite, meanwhile, struggled against Mephiles’ cosmic pull draining the energy from his body. “ _ How dare you intervene?! _ ” he shouted inwardly. The obsidian pulsed like waves of nausea.

Mephiles’ voice echoed back, sharp as cleaving stone:  _ DO NOT HURT HIM YET. HE STILL SERVES A PURPOSE.  _

“ _ Oh, what great purpose could he serve that would not bear a little torture?” _

The cold snap of the in-between cracked across Infinite. He left the snowy woods with its still-hunched body and whirled across timespace by the anchor bound at his chest. The mercenary declined to take a swipe at Mephiles’ form when the latter coalesced in the void, though he did fancy the idea. 

_ SHADOW IS BOTH MY CAPTOR AND MY FREEDOM. OUR FATES ARE INEXPLICABLY TIED. DO NOT CHANGE THIS.  _

Infinite let a growl simmer in the back of his throat.

_ YOUR HOUR OF REVENGE WILL COME SOON ENOUGH. GO, AND DO NOT FAIL ME. _

Infinite braced himself for the impact against Soleanna’s cobblestones. He raised one hand to ward off the annoyingly bright festival lights. The phantom obsidian told him, in not so many words, that the first opportunity to end the blue blur was nigh. He received a location. A time. Infinite pushed himself up off the ground. He vaguely dusted himself back into a full display of pride.

“I could just  _ kill _ for a good murder right now,” he snarled.

**Notes for the Chapter:**

> Thank you thank you thank you to everyone who read and enjoyed chapter 1! Your kind messages helped me get through the last couple of months, and I'm so excited to finally post more of this story. Infinite is an absolute delight to write for. (Self-important power hungry bastard that he is.)


End file.
